Apparatus that automatically controls the correlation between time and airpressure



Feb. 6, 1968 KAZUHlRo MORIYAMA ET AL 3,367,367

APPARATUS THAT AUTOMATICALLY CONTROLS THE CORRELATION BETWEEN TIME ANDAIR-PRESSURE Filed Nov. 25, 1963 2 Sheets-Sheet 1 INVENTORS KAZUHIROMORIYAMA TOSHIMITSU HORI BY fiJ/W ATTORNEYS Feb. 6, 1968 KAZUHIROMORlYAMA ET AL 3,367,367

APPARATUS THAT AUTOMATICALLY CONTROLS THE CORRELATION BETWEEN TIME ANDAIRPRESSURE Filed Nov; 25, 1963 2 Sheets-Sheet 2 FIG. 2

SECONDARY SIDE 3 PRESSURE Kg/ g M 0 ON (SWITCH) OFF ON OFF l E(Sec)INVENTORS KAZU HIRO MORIYA MA TOSHIMITSU HORI ATTO R N EYS United StatesPatent 3,367,367 APPARATUS THAT AUTOMATICALLY CONTROLS THE CORRELATIONBETWEEN TIME AND AIR- PRESSURE Kazuhiro Moriyama and Toshimitsu Hori,Tokyo-to,

Japan, assignors to Ishikawajima-Harima Jukogyo Kabushiki Kaisha,Tokyo-to, Japan, a company of Ja an F Filed Nov. 25, 1963, Ser. No.325,822

4 Claims. (Cl. 137--614.11)

This invention relates to the apparatus that automatically controls thecorrelation between time and air-pressure, and which is fit for anautomatic controlling of the pressure to be charged especially at thetime of low-pressure die casting.

As is well-known, in the case of low-pressure die casting, it isrequired that, in order to fill up the cavity with molten metal,air-pressure of 0-1 l g./crn. should be applied to the surface of themolten metal in the crucibles, and that the pressure should be kept atgiven height for a fixed period.

In such pressure-method, the pressure-valve is usually opened by hand,but, then, as it is difficult to control pressure, and, as the pressuretends to be given in too short time, the results are not always good,which is one of the great deficiencies of such method.

It is one of the objects of the present invention to provide arising-curve of the pressure which is automatically controlled againsttime, and by which the uniformity of the quality and mass production areachieved.

FIG. 1 is a sectional view of an example of the automatic pressurecontrolling valve and the three-Way change-over valve.

FIG. 2 is a block-diagram of a complete installation.

FIG. 3 is a diagram which shows the action of the automatic pressurecontrolling valve.

Explanations will be given hereafter about one embodiment of theinvention referring to the attached figures.

FIG. 1 shows the automatic pressure controlling valve A hereafter to becalled simply controlling valve, and the three-way change-over valve Bhereafter to be called simply change-over valve, and the latter consistsof a four-way electro-magnetic change-over valve for air C and thethree-way stop-valve D.

The said controlling-valve A is provided with the upper oil-chamber 3and the lower oil-chamber 4 between the upper air-chamber 1 and thelower air-chamber 2, and the upper air-chamber 1 and the upperoil-chamber 3, as well as the lower air-chamber 2 and the loweroil-chamber 4, are divided from each other by the plastic diaphragms 6which are connected with the stem that can move vertically.

The upper and the lower coil-chambers 3 and 4 are connected with eachother, the opening of the passage between them being controlled by thecontrolling-needle 7. And both are connected with each other through theoneway check-valve 8.

The vertical motion of the said stem 5 is restricted by the lower stop 9and the upper stop 10 which can be controlled freely, but the lower endof the stem 5 is connected with the spring holder 11 engaging one end ofa spring 12 which forms a pressure means. The other end of the spring 12is held by the plate 14 of the diaphragm 13 receiving the secondarypressure, and the said plate is raised by the bolt 15 when the stem 5goes up. And with the said plate is connected the relief valve seat 16,and the needle 17 of the relief valve is pressed against the valve seat16 by the spring 19 with the diaphragm 18 in between. The port E for thecompressed air of the primary side is connected with the compressed-airchamber T (FIG. 2).

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The said upper and lower air-chamber 1 and 2 are each connected with thetwo ports of the four-way electromagnetic change-over valve C, while theother two ports of the electric-magnetic valve C are each connected withupper cylinder-chamber 21 and the lower cylinder-room 22 which aredivided by the piston 20 of the three-way change-over stop valve D.

One port a of the three-way change-over stop valve D is connected withthe pressure chamber of secondary side F of the said controlling valveA, another port b with the controlled side G (FIG. 2) such as a furnacefor example, and the remaining port c with the outside atmosphere. Thevalve body 23 of the stop valve D, its upper valve seat 24 and lowervalve seat 25 are shown at the lower right of FIG. 1.

The magnet 26 coacts with spool 27 of the electromagnetic valve 0 whichis pushed down by the movable core of the magnet 26 and is retracted bythe retracting spring 28. The port 29 for the air on the primary side,the exhaust port 30, the push-button switch S of the magnet 26, themotor M, the compressor P, the filter Q, the reducing valve N, and thelubricator L are all indicated in FIG. 2.

The operation of an embodiment of the present invention is set forthbelow.

First, when the push-button switch S is closed, the magnet 26 of thechange-over valve B is put into operation, and the movable core thereoflowers spool 27. When the spool 27 comes down to its lower position, theairpressure from the port 29 is introduced into the upper air-chamber 1of the controlling valve and the upper cylinder-chamber 21, and, at thesame time, the air-pressure of the lower air-chamber 2 and the lowercylinderchamber 22 is discharged into the atmosphere through the exhaustport 30.

The result is that the piston 20 is pushed down and the valve body 23 isset on the lower valve seat 25 and the secondary air-pressure from thecontrolling valve A is transmitted to the furnace, the controlled sideG, through the valve B.

By the air-pressure, introduced into the upper air-room 1, a downwardthrust is given on the stem 5 of the diaphragm-motor, and at the sametime, the oil in the upper oil-chamber is given pressure, and the saidpressed oil fiows into the lower oil-chamber 4 through the orificeprovided by the controlling needle 7 in the opening, and, accordingly,the stem 5 begins to lower at a constant speed.

The lowering speed of the stem 5 can be regulated minutely bycontrolling the opening of the orifice by the controlling needle 7properly.

Now, when the stem 5 lowers, the spring holder 11 on its tip is pusheddown and the spring 12 is gradually pressed and the additional pressureupon the diaphragm 13 receiving the secondary pressure increases inproportion with the distance the stem has lowered, and, therefore, thepressure on the controlled side increases in accordance with time. Whenthis rising of the secondary pressure reaches the given highest degree,the lowering of the stem 5 is held by the stop 9, and, therefore, thepressure no longer rises and the fixed pressure can be kept on until theswitch S is opened.

How the secondary pressure rises is shown on the diagram of FIG. 3.

If the switch S is opened, the magnet ceases to be in operation, and themovable core and the spool 27 are pushed up by the retracting spring 28,and then the airpressure from the primary side flows into the lowercylinder-chamber 22 and the lower air-chamber 2 and the air- 0 pressureof the upper cylinder-chamber 21 and the upper Therefore the stem isgiven an upward thrust and the oil in the lower oil-chamber 4 is givenpressure and, pushing open the check-valve 8, flows fast into the upperoilroom 3, and so the stem 5 rises up rapidly until it collides againstthe upper stop 10.

At the final point of its rising, the stem 5 pulls up thediaphragm-plate 14, the relief valve seat 16 moves at the same time (asit is connected with the former), and the relief-valve is opened andthrough it secondary airpressure is discharged into the atmosphere atonce.

Here, one cycle of operation is finished, and the pressure on thecontrolled side becomes zero, and in this condition the new cycle is tobe begun.

The highest pressure to be introduced into the controlled side G can beeasily controlled by regulating the lower stop 9, changing the stokes ofthe stem, and adjusting the flexure of the spring 12. And the timerequired to reach the highest pressure from zero can be regulatedproperly by adjusting the Opening of the orifice between the upper andlower oil-chambers 3 and 4 with the controlling needle 7 (it is a matterof course that it can be adjusted by other means), and the duration ofthe highest pressure can be controlled by adjusting the opening time ofthe switch S, and so it is possible to control easily and automaticallythe correlation between time and pressure shown in FIG. 3.

In the case of the present invention, as distinct from reducing valvesof the usual type, the secondary pressure is completely relieved of theinfluence of the pressure on the primary side, and, therefore, thesecondary pressure cannot be made lower than a given degree, and, as thediameter of the diaphragm 13 receiving the secondary pressure can bemade long, its sensibility is sharp and the error in the given pressureis very small and the proper quantity of the flow can be maintained.

Thus, it will seen that the ports E and F as well as the ports a and 12form together with the connections therebetween a delivery conduit meansthrough which a fluid is delivered to a required delivery location, andthe valve 23 forms a delivery valve means which coacts with this conduitmeans to open and close the latter so as to initiate and terminate theflow of fluid therethrough. The diaphragm 13 is a pressure-responsivemeans which controls the pressure of the fluid in the delivery conduitmeans which includes the ports E, F, a and b, and this latterpressure-responsive means 13 communicates with the latter conduit meansto act on the fluid thereof and is in turn acted upon by 'a pressuremeans formed by the spring 12 which acts to control the pressuretransmitted to the fluid in the conduit means by Way of thepressureresponsive means 13. The chamber 1 is a working chamber meanswhich receives a working fluid, which is at suitable pressure, from theworking fluid supply means B, and a pressure-responsive means is formedby the upper diaphragm 6 of FIG. 1 to respond to the introduction ofworking pressure fluid in the working chamber 1. The chamber 3, togetherwith the adjustable valve 7 form a control means for controlling therate of response of the pressure-responsive means formed by the upperdiaphragm 6 of FIG. 1 to the introduction of fluid under pressure intothe working chamber means 1, and this control means formed by thechamber means 3 and the valve means 7 will control the time it takes forthe stem 5 to be displaced through a given increment of movement. Thisstem 5 forms a motion-transmitting means which transmits the motion ofthe upper diaphragm 6 of FIG. 1 to the pressure means 12 for increasingthe pressure of the latter as the volume of the working chamber means 1increases, so that as a result of the control means 3, 7 the rate ofincrease of the force exerted by the ressure means 12 on thepressure-responsive means 13 is regulated, and thus it is possible toregulate the rate at which the pressure increases in the fluid flowingalong the conduit which includes the ports E, P.

The three-way change-over valve B is very compact, as the four-waychange-over electro-m'agnetie valve C and the three-way change-overstop-valve D are incorporated into one, and, as the direction of thedischarge of hightemperature air is downward, the movable parts cannever be exposed to the heat directly, and the seal is complete.

Though the foregoing explanations are mainly about the cases in whichthe present invention is used in the controlling of the pressure to beintroduced in the case of low-pressure die casting, it is a matter ofcourse that the present invention can be put into practical use invarious fields, and it goes without saying that each constituent of thesaid embodiment of the present invention may take other types if withinthe idea of the original invention. 1

What I claim is:

1. In an apparatus for delivering a fluid to a given location Whilecontrolling the time required for a pressure of the fluid to rise to agiven extent, delivery conduit means through which a fluid is deliveredto a given location, delivery valve means coacting with said deliveryconduit means for opening and closing the latter, so that when saiddelivery valve means is open the fluid will flow through said deliveryconduit means to said location, first pressure-responsive meanscommunicating with said conduit means and controlling the pressure ofthe fluid flowing therethrough, pressure means acting on said firstpressure-responsive means for controlling the pressure which said firstpressure-responsive means maintains in the fluid flowing through saiddelivery conduit means, working chamber means, supply meanscommunicating with said working chamber means for supplying a workingpressure fluid thereto, second pressure-responsive means communicatingwith said working chambers means for responding to the supply of workingfluid thereto and for moving in response to an increase in the volume ofsaid working chamber means during supply of working fluid thereto,motion transmitting means coacting with said second pressure-responsivemeans and with said pressure means for increasing the pressure of saidpressure means and thus increasing the pressure transmitted by saidfirst pressure-responsive means to the fluid in said delivery conduitmeans as the volume of said working chamber means increases, and controlmeans acting on said pressure-responsive means for controlling the rateat which the latter moves in response to flow of working pressure fluidinto said working chamber means, so that said control means regulatesthe time required for the pressure of the fluid flowing through saiddelivery conduit means to rise to a given value.

2. The combination of claim 1 and wherein said first and second pressureresponsive means are respectively in the form of first and seconddiaphragms, said pressure means being in the form of a spring, and saidworking chamber means being an air chamber which receives air underpressure to displace said second diaphragm, said motion transmittingmeans including an elongated stem operatively connected with said seconddiaphragm and with said spring for stressing the latter to an increasingdegree as the volume of said working chamber means increases, saidcontrol means including an oil chamber situated at the side of saidsecond diaphragm opposite from said air chamber so that as said seconddiaphragm moves in response to an increase in the volume of said airchamber it simultaneously moves to decrease the volume of said oilchamber, and said control means including an addition to said oilchamber an adjustable v'alve which communicates with said oil chamber tocontrol the rate at which oil flows out of the latter as said seconddiaphragm responds to an increase in the volume of said working chamber.

3. The combination of claim 2 and wherein a second oil chambercommunicates with said adjustable valve of said control means forreceiving the oil therefrom, and a second air chamber adapted to beplaced in communication With said supply means when the communicationbetween the latter and said first-mentioned air chamber is terminated, athird diaphragm situated between and separating said second oil chamberand said second air chamber from each other so that as the volume ofsaid second oil chamber increases the volume of said second air chamberdecreases and air is discharged therefrom, said third diaphragm beingoperatively connected to said stem for movement therewith and moving inunison with said second diaphragm so that as oil flows from saidfirst-mentioned oil chamber through said adjustable valve of saidcontrol means into said second oil chamber the volume of said second airchamber decreases while the volume of said first-mentioned air chamberincreases and the pressure provided by said first diaphragm on the fluidin said delivery conduit means increases at a rate determined by thesetting of said valve of said control means, and change-over meanscoacting with said supply means for changing the latter over from 'anoperative connection with said first-mentioned air chamber to anoperative connection with said second air chamber, said change-overmeans coacting with said delivery valve means for closing the latterwhen said supply conduit means is placed in communication with saidsecond air chamber, and check-valve means for providing a communicationbetween both of said oil chambers and for providing a rapid flow of oilfrom said second oil chamber to said first-mentioned oil chamber duringan increase in the volume of said second air chamber when the latter isplaced by said change-over means in communication with said supplymeans, said change-over means placing said first-mentioned air chamberin communication with a source of low pressure so that the air will bedischarged therefrom as the oil flows rapidly through said check-valvemeans from said second to said first-mentioned oil chamber, whereby theincreased pressure on said pressure means is relieved, said deliveryvalve means closes, and the pressure of the fluid in said deliveryconduit means drops.

4. The combination of claim 3 and wherein a relief valve means coactswith said first pressure-responsive means and with said delivery conduitmeans for placing the interior of the latter in communication with theouter atmosphere when said change-over means places said supply means incommunication with said second air chamber.

References Cited UNITED STATES PATENTS 3/1939 Riches 137-1165 2/1950Heller l37---613

1. IN AN APPARATUS FOR DELIVERING A FLUID TO A GIVEN LOCATION WHILECONTROLLING THE TIME REQUIRED FOR A PRESSURE OF THE FLUID TO RISE TO AGIVEN EXTENT, DELIVERY CONDUIT MEANS THROUGH WHICH A FLUID IS DELIVEREDTO A GIVEN LOCATION, DELIVERY VALVE MEANS COACTING WITH SAID DELIVERYCONDUIT MEANS FOR OPENING AND CLOSING THE LATTER, SO THAT WHEN SAIDDELIVERY VALVE MEANS IS OPEN THE FLUID WILL FLOW THROUGH SAID DELIVERYCONDUIT MEANS TO SAID LOCATION, FIRST PRESSURE-RESPONSIVE MEANSCOMMUNICATING WITH SAID CONDUIT MEANS AND CONTROLLING THE PRESSURE OFTHE FLUID FLOWING THERETHROUGH, PRESSURE MEANS ACTING ON SAID FIRSTPRESSURE-RESPONSIVE MEANS FOR CONTROLLING THE PRESSURE WHICH SAID FIRSTPRESSURE-RESPONSIVE MEANS MAINTAINS IN THE FLUID FLOWING THROUGH SAIDDELIVERY CONDUIT MEANS, WORKING CHAMBER MEANS, SUPPLY MEANSCOMMUNICATING WITH SAID WORKING CHAMBER MEANS FOR SUPPLYING A WORKINGPRESSURE FLUID THERETO, SECOND PRESSURE-RESPONSIVE MEANS COMMUNICATINGWITH SAID WORKING CHAMBERS MEANS FOR RESPONDING TO THE SUPPLY OF WORKINGFLUID THERETO AND FOR MOVING IN RESPONSE TO AN INCREASE IN THE VOLUME OFSAID WORKING CHAMBER MEANS DURING SUPPLY OF WORKING FLUID THERETO,MOTION TRANSMITTING MEANS COACTING WITH SAID SECOND PRESSURE-RESPONSIVEMEANS AND WITH SAID PRESSURE MEANS FOR INCREASING THE PRESSURE OF SAIDPRESSURE MEANS AND THUS INCREASING THE PRESSURE TRANSMITTED BY SAIDFIRST PRESSURE-RESPONSIVE MEANS TO THE FLUID IN SAID DELIVERY CONDUITMEANS AS THE VOLUME OF SAID WORKING CHAMBER MEANS INCREASES, AND CONTROLMEANS ACTING ON SAID PRESSURE-RESPONSIVE MEANS FOR CONTROLLING THE RATEAT WHICH THE LATTER MOVES IN RESPONSE TO FLOW OF WORKING PRESSURE FLUIDINTO SAID WORKING CHAMBER MEANS, SO THAT SAID CONTROL MEANS REGULATESTHE TIME REQUIRED FOR THE PRESSURE OF THE FLUID FLOWING THROUGH SAIDDELIVERY CONDUIT MEANS TO RISE TO A GIVEN VALUE.